The present invention relates generally to work tables for power tools and the like, and is more particularly directed to a combination workpiece positioning/hold-down and anti-kickback device for a work table.
A work table for a woodworking device, such as a power saw, router and the like, generally includes a horizontal tabletop on which the workpiece is supported and a fence secured to the tabletop and extending in the direction of movement of the workpiece. The workpiece is moved on the upper surface of the tabletop and is guided along the fence, during a cutting or other woodworking action.
Featherboard and other devices are known for pressing the workpiece against the fence during such movement, and various hold-down devices are known for pressing the upper surface of the workpiece to hold the workpiece down on the tabletop. These devices have some of the following desirable features.
One such desirable feature is the ability to prevent kick-back of the workpiece during a woodworking operation. Another desirable feature is the adjustment of the positioning or hold-down member in lengthwise, transverse and vertical directions relative to the workpiece. Still another desirable feature is the ability to variably adjust the biasing force of the positioning or hold-down member against the workpiece. The applicant is not aware, however, of any devices that include all of these features in a simple arrangement.
Accordingly, it is an object of the present invention to provide a combination workpiece positioning/hold-down and anti-kickback device that overcomes inherent disadvantages of know workpiece positioning/hold-down devices.
It is another object of the present invention to provide a combination workpiece positioning/hold-down and anti-kickback device that presses the side and/or top surface of the workpiece, while preventing kick-back thereof.
It is still another object of the present invention to provide a combination workpiece positioning/hold-down and anti-kickback device in which the positioning or hold-down member is adjustable in lengthwise, transverse and vertical directions relative to the workpiece.
It is yet another object of the present invention to provide a combination workpiece positioning/hold-down and anti-kickback device in which the biasing force of the positioning or hold-down member against the workpiece is variably adjustable.
In accordance with one form of the present invention, a combination workpiece positioning and anti-kickback device for a work table having a fence against which a workpiece is guided includes a positioning member having a main body, and an arcuate cam surface at one edge of the main body for engaging a side surface of a workpiece on the work table; an adjustment device for moving the positioning member relative to the workpiece, the adjustment device including: a lengthwise adjustment assembly movable in a lengthwise direction of movement of the workpiece along the work table for adjusting the position of the positioning member in said lengthwise direction, and a transverse adjustment assembly movable in a direction transverse relative to said lengthwise direction for adjusting the position of the positioning member in the transverse direction, the transverse adjustment assembly being connected to the lengthwise adjustment assembly; a lengthwise releasable locking device for releasably locking the lengthwise adjustment assembly relative to the work table at a desired location in the lengthwise direction; a transverse releasable locking device for releasably locking the transverse adjustment assembly relative to the work table at a desired location in the transverse direction; a pivot which pivotally mounts the positioning member to the adjustment device for pivoting movement; and a spring for biasing the positioning member with a biasing force in a first pivot direction about said pivot such that said arcuate cam surface is biased in a direction opposite to a feed direction of said workpiece and into engagement with the side surface of the workpiece; wherein said lengthwise adjustment assembly includes at least first and second lengthwise adjustment members, the first lengthwise adjustment member being received within an interior portion of the second lengthwise adjustment member.
In accordance with another form of the present invention, a combination workpiece hold-down and anti-kickback device for a work table having a fence against which a workpiece is guided includes a hold-down member having a main body, and an arcuate cam surface at one edge of the main body for engaging an upper surface of a workpiece on the work table; an adjustment device for moving the hold-down member relative to the workpiece, the adjustment device including a lengthwise adjustment assembly movable in a lengthwise direction of movement of the workpiece along the work table for adjusting the position of the hold-down member in said lengthwise direction, a transverse adjustment assembly movable in a direction transverse to said lengthwise direction for adjusting the position of the hold-down member in the transverse direction, the transverse adjustment assembly being connected to the lengthwise adjustment assembly; a vertical adjustment assembly movable in a vertical direction transverse to said lengthwise and transverse directions for adjusting the position of the hold-down member in the vertical direction, the vertical adjustment assembly being movably connected to the transverse lengthwise adjustment assemblies; a lengthwise releasable locking device for releasably locking the lengthwise adjustment assembly relative to the work table at a desired location in the lengthwise direction; a transverse releasable locking device for releasably locking the transverse adjustment assembly relative to the worktable at a desired location in the transverse direction; a vertical releasable locking device for releasably locking the vertical adjustment assembly relative to the work table at a desired location in the vertical direction; a pivot which pivotally mounts the hold-down member to the adjustment device for pivoting movement; and a spring for biasing the hold-down member with a biasing force in a first pivot direction about said pivot such that said arcuate cam surface is biased in a direction opposite to a feed direction of said workpiece and into engagement with the upper surface of the workpiece.
In accordance with another form of the present invention, a combination workpiece positioning, hold-down and anti-kickback device for a work table having a fence against which a workpiece is guided, comprising a positioning member having a main body, and an arcuate cam surface at one edge of the main body for engaging a side surface of a workpiece on the work table; an adjustment device for moving the positioning member relative to the workpiece, the adjustment device including a lengthwise adjustment assembly movable in a lengthwise direction of movement of the workpiece along the work table for adjusting the position of the positioning member in said lengthwise direction, and a transverse adjustment assembly movable in a direction transverse relative to said lengthwise direction for adjusting the position of the positioning member in the transverse direction, the transverse adjustment assembly being movably connected to the lengthwise adjustment assembly; a lengthwise releasable locking device for releasably locking the lengthwise adjustment assembly relative to the work table at a desired location in the lengthwise direction; a transverse releasable locking device for releasably locking the transverse adjustment assembly relative to the work table at a desired location in the transverse direction; a pivot which pivotally mounts the positioning member to the adjustment device for pivoting movement; a spring for biasing the positioning member with a biasing force in a first pivot direction about said pivot such that said arcuate cam surface is biased in a direction opposite to a feed direction of said workpiece and into engagement with the side surface of the workpiece; a hold-down member having a main body, and an arcuate cam surface at one edge of the main body for engaging an upper surface of the workpiece on the table; an adjustment device for moving the hold-down member relative to the workpiece, the adjustment device including a lengthwise adjustment assembly movable in a lengthwise direction of movement of the workpiece along the work table for adjusting the position of the hold-down member in said lengthwise direction, a transverse adjustment assembly movable in a direction transverse to said lengthwise direction for adjusting the position of the hold-down member in the transverse direction, the transverse adjustment assembly being movably connected to the lengthwise adjustment assembly; and a vertical adjustment assembly movable in a vertical direction transverse to said lengthwise and transverse directions for adjusting the position of the hold-down member in the vertical direction, the vertical adjustment assembly being movably connected to the transverse lengthwise adjustment assemblies; a lengthwise releasable locking device for releasably locking the lengthwise adjustment assembly relative to the work table at a desired location in the lengthwise direction; a transverse releasable locking device for releasably locking the transverse adjustment assembly relative to the worktable at a desired location in the transverse direction; a vertical releasable locking device for releasably locking the vertical adjustment assembly relative to the work table at a desired location in the vertical direction; a pivot which pivotally mounts the hold-down member to the adjustment device for pivoting movement; and a spring for biasing the hold-down member with a biasing force in a first pivot direction about said pivot such that said arcuate cam surface is biased in a direction opposite to a feed direction of said workpiece and into engagement with the upper surface of the workpiece, wherein said lengthwise adjustment assembly includes at least first and second lengthwise adjustment members, the first lengthwise adjustment member being received within an interior portion of the second lengthwise adjustment member; and wherein a hold-down member having a main body, and an arcuate cam surface at one edge of the main body for engaging an upper surface of a workpiece on the work table.
The above and other objects, features and advantages of the present invention will become readily apparent from the following detailed description of the illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.